Negative correlation refers to a relationship between two things where they go in the opposite direction. So when one thing increases, the other thing decreases, and vice versa.
The very high maximum temperatures during 2002 could not simply be attributed to the low rainfall, although there is a strong negative correlation between rainfall and maximum temperature. (ipcc.ch)
It has the added benefit of a long history of negative correlation with momentum. (blackrock.com)
In education, we are always hearing about research that points out a strong negative correlation between poverty and student achievement. (educationnorthwest.org)